1. Field of the Invention
The present invention is directed in general to wireless communication systems. In one aspect, the present invention relates to a method and system for incorporating one or more antennas into an integrated circuit used in a wireless communication system.
2. Related Art
Communication systems are known to support wireless and wire-lined communications between wireless and/or wire-lined communication devices. Such communication systems range from national and/or international cellular telephone systems to the Internet to point-to-point in-home wireless networks. Each type of communication system is constructed, and hence operates, in accordance with one or more communication standards. For instance, wireless communication systems may operate in accordance with one or more standards including, but not limited to, IEEE 802.11, Bluetooth (BT), advanced mobile phone services (AMPS), digital AMPS, global system for mobile communications (GSM), code division multiple access (CDMA), local multi-point distribution systems (LMDS), multi-channel-multi-point distribution systems (MMDS) and/or variations thereof.
Depending on the type of wireless communication system, a wireless communication device (such as a cellular telephone, two-way radio, personal digital assistant (PDA), personal computer (PC), laptop computer, home entertainment equipment, etc.) communicates directly or indirectly with other wireless communication devices. For direct communications (also known as point-to-point communications), the participating wireless communication devices tune their receivers and transmitters to the same channel or channels (e.g., one of the plurality of radio frequency (RF) carriers of the wireless communication system) and communicate over the tuned channel(s). For indirect wireless communications, each wireless communication device communicates directly with an associated base station (e.g., for cellular services) and/or an associated access point (e.g., for an in-home or in-building wireless network) via an assigned channel. To complete a communication connection between the wireless communication devices, the associated base stations and/or associated access points communicate with each other directly, via a system controller, via the public switched telephone network, via the Internet, and/or via some other wide area network.
Wireless communication devices typically communicate with one another using a radio transceiver (i.e., receiver and transmitter) that may be incorporated in, or coupled to, the wireless communication device. The transmitter typically includes a data modulation stage, one or more intermediate frequency stages and a power amplifier. The data modulation stage converts raw data into baseband signals in accordance with a particular wireless communication standard. The intermediate frequency stages mix the baseband signals with one or more local oscillations to produce RF signals. The power amplifier amplifies the RF signals prior to transmission via an antenna. In direct conversion transmitters/receivers, conversion directly between baseband signals and RF signals is performed. The receiver is typically coupled to an antenna and includes a low noise amplifier, one or more intermediate frequency stages, a filtering stage and a data recovery stage. The low noise amplifier receives inbound RF signals via the antenna and amplifies them. The intermediate frequency stages mix the amplified RF signals with one or more local oscillations to covert the amplified RF signal into baseband signals or intermediate frequency (IF) signals. The filtering stage filters the baseband signals or the IF signals to attenuate unwanted out of band signals to produce filtered signals. The data recovery stage recovers raw data from the filtered signals in accordance with the particular wireless communication standard.
Wireless communication systems are typically implemented using one or more integrated circuits. Antenna placement and orientation is essential to obtain adequate signal strength to enable operation of the wireless communication system. In addition, as space constraints limit the size of the components used in wireless devices, antenna placement and orientation is a serious constraint.
Maintaining proper antenna orientation is a significant problem for portable devices such as laptop computers and personal digital assistants (PDAs) that are constantly being moved, thereby changing the orientation of the antennas used to receive the RF signals. As will be understood by those of skill in the art, RF signals have a polarization and the antenna must be properly oriented with respect to this polarization to maximize the signal strength. To maximize the likelihood of receiving a strong RF signal, many transceiver use multiple antenna elements that have physical characteristics that are tuned to maximize the RF signal strength at a particular frequency. However, prior art systems have not provided a system for ensuring proper orientation of antennas in portable wireless communication devices to ensure maximum RF signal strength.
The problems discussed above with regard to antenna placement are exacerbated in systems that include two or more radio transceivers with two or more antennas. Many wireless devices currently use two or more radio transceivers, where each radio transceiver is compliant with any of a variety of wireless communication standards may be used with the exemplary communication systems described herein, including Bluetooth, IEEE 802.11(a), (b), (g) and others. For instance, a computer may include two radio transceivers, one for interfacing with an 802.11a wireless local area network (WLAN) device and another for interfacing with an 802.11g WLAN device. In this example, the 802.11g transceiver operates in the 2.4 GHz frequency range and the 802.11a transceiver operates in the 5 GHz frequency range.
In view of the foregoing, there is a need for an improved method and apparatus for placing an antenna in an integrated circuit substrate and for orienting antennas on the integrated circuit to ensure maximum signal strength. Further limitations and disadvantages of conventional systems will become apparent to one of skill in the art after reviewing the remainder of the present application with reference to the drawings and detailed description which follow.